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Write the word equation from the Write the word equation from the following description:following description:Zinc metal is added to hydrochloric Zinc metal is added to hydrochloric acid to create zinc chloride and acid to create zinc chloride and hydrogen gas.hydrogen gas.

Ch. 8 Chemical Ch. 8 Chemical Equations and ReactionsEquations and Reactions

8.1b Balancing Equations and 8.1b Balancing Equations and Writing Formula EquationsWriting Formula Equations

Balancing EquationsBalancing Equations Skittle method works great . . . Skittle method works great . . . But there is also But there is also MINOHMINOH

1.1. MetalsMetals

2.2. Ions, specifically of the polyatomic Ions, specifically of the polyatomic variety variety (see p. 210 for a refresher) (see p. 210 for a refresher)

3.3. Non-metals (except oxygen & Non-metals (except oxygen & hydrogen)hydrogen)

4.4. Oxygen & Hydrogen are saved for lastOxygen & Hydrogen are saved for last

Writing EquationsWriting Equations1.1. Write word equation to help you Write word equation to help you

organize reactants and productsorganize reactants and products

2.2. Include symbols showing states of Include symbols showing states of each reactant and producteach reactant and product

3.3. Write the correct formula for each Write the correct formula for each (review chapter 7)(review chapter 7)

4.4. Balance the equationBalance the equation

Example 1Example 1

Description:Description:

Zinc metal is added to hydrochloric Zinc metal is added to hydrochloric acid to create zinc chloride and acid to create zinc chloride and hydrogen gas.hydrogen gas.

Word Equation:Word Equation:

zinc + hydrochloric acid zinc + hydrochloric acid

zinc chloride + zinc chloride + hydrogenhydrogen

Example 1Example 1 Formula Equation:Formula Equation:

Zn (s) + HCl(aq) Zn (s) + HCl(aq) ZnCl ZnCl22(aq) + H(aq) + H22(g)(g) Balanced Formula EquationBalanced Formula Equation

Zn (s) + 2HCl(aq) Zn (s) + 2HCl(aq) ZnCl ZnCl22(aq) + (aq) + HH22(g)(g)

Example 2Example 2 Solid calcium metal reacts with water Solid calcium metal reacts with water

to form aqueous calcium hydroxide to form aqueous calcium hydroxide and hydrogen gas.and hydrogen gas.

calcium + water calcium + water

calcium hydroxide + calcium hydroxide + hydrogenhydrogen

Ca(s) + HCa(s) + H22O(l) O(l) Ca(OH) Ca(OH)22(aq) + H(aq) + H22(g)(g)

Ca(s) + 2HCa(s) + 2H22O(l) O(l)

Ca(OH)Ca(OH)22(aq) + H(aq) + H22(g)(g)

Example 3Example 3 solid zinc metal reacts with aqueous solid zinc metal reacts with aqueous

copper (II) sulfate to produce solid copper copper (II) sulfate to produce solid copper metal and aqueous zinc sulfatemetal and aqueous zinc sulfate

zinc + copper (II) sulfate zinc + copper (II) sulfate

copper + zinc sulfatecopper + zinc sulfate Zn(s) + CuSOZn(s) + CuSO44(aq) (aq) Cu(s) + ZnSO Cu(s) + ZnSO44(aq)(aq)

Zn(s) + CuSOZn(s) + CuSO44(aq) (aq) Cu(s) + ZnSO Cu(s) + ZnSO44(aq)(aq)

Example 4Example 4

Aqueous hydrogen Aqueous hydrogen peroxide decomposes to peroxide decomposes to produce oxygen and waterproduce oxygen and water

hydrogen peroxide hydrogen peroxide oxygen + wateroxygen + water

HH22OO22(aq) (aq) O O22(g) + H(g) + H22O(l)O(l)

2H2H22OO22(aq) (aq) O O22(g) + (g) + 2H2H22O(l)O(l)

Example 5Example 5

Solid copper metal reacts with Solid copper metal reacts with aqueous silver nitrate to produce aqueous silver nitrate to produce solid silver metal and aqueous solid silver metal and aqueous copper (II) nitratecopper (II) nitrate

copper + silver nitrate copper + silver nitrate silver + copper (II) silver + copper (II)

nitratenitrate

Example 5Example 5

Cu(s) + AgNOCu(s) + AgNO33(aq) (aq) Ag(s) + Ag(s) + Cu(NOCu(NO33))22(aq)(aq)

Cu(s) + 2AgNOCu(s) + 2AgNO33(aq) (aq) 2Ag(s) + 2Ag(s) + Cu(NOCu(NO33))22(aq)(aq)

Example 6Example 6

Carbon dioxide gas is bubbled through Carbon dioxide gas is bubbled through water containing solid barium carbonate, water containing solid barium carbonate, creating aqueous barium bicarbonatecreating aqueous barium bicarbonate

carbon dioxide + water + barium carbon dioxide + water + barium carbonate carbonate barium bicarbonate barium bicarbonate

COCO22(g) + H(g) + H22O(l) + BaCOO(l) + BaCO33(s) (s) Ba(HCOBa(HCO33))22(aq)(aq)

COCO22(g) + H(g) + H22O(l) + BaCOO(l) + BaCO33(s) (s) Ba(HCOBa(HCO33))22(aq)(aq)

Example 7Example 7 Acetic acid solution is added to a solution of Acetic acid solution is added to a solution of

magnesium bicarbonate to create water, magnesium bicarbonate to create water, carbon dioxide gas, and aqueous carbon dioxide gas, and aqueous magnesium acetate.magnesium acetate.

acetic acid + magnesium bicarbonate acetic acid + magnesium bicarbonate water + carbon dioxide + magnesium acetatewater + carbon dioxide + magnesium acetate HCHHCH33COO(aq) + Mg(HCOCOO(aq) + Mg(HCO33))22(aq) (aq)

HH22O(l) + COO(l) + CO22(g) + Mg(CH(g) + Mg(CH33COO)COO)22(aq)(aq) 2HCH2HCH33COO(aq) + Mg(HCOCOO(aq) + Mg(HCO33))22(aq) (aq)

2H2H22O(l) + 2COO(l) + 2CO22(g) + Mg(CH(g) + Mg(CH33COO)COO)22(aq)(aq)